In automation systems or in the Internet of Things, applications or devices are to be protected against IT attacks. In this environment, stringent requirements often apply to latency or delay of the data communication. Simple devices equipped with little processing capacity are often provided in the Internet of Things. In order to achieve a sufficient level of protection, it is neither practicable nor economical in many application scenarios to protect each individual small system or each individual data packet or each individual communication connection sufficiently robustly against attacks. Additionally provided cryptographic protective measures frequently cannot be retrofitted in a simple manner, particularly in the case of old devices or external devices. Even if integrated security solutions are used, the level of protection is often not sufficient, since control software may be manipulated or cryptographic keys for protecting a communication may be compromised in the automation system environment.
From Offenlegungsschrift (patent application, unexamined and first publication) DE 10 2010 033229 A1, it is known to obtain integrity-checking information for control data, said information being transmitted in a cryptographically protected form and checked. The check is carried out separately from the control data to be transmitted.
It is furthermore known from patent specification DE 10 2009 039097 B3 to provide a cryptographically protected data structure over a value range in addition to the transmission of the unsecured measured values. The cryptographically protected data structure over the value range can be used to check measured values that are predictable for a specific time period.